It is known that an electrical arcing phenomenon is the result of slow deterioration of the insulation of cables used to distribute alternating current or direct current electrical energy caused by an aggressive environment (moisture in the air, mildew, rubbing, vibration of the connecting terminals, varying temperatures, shear, etc.).
The electrical arcing phenomenon is divided into four successive phases of increasing energy:                a corona discharge phase corresponding to the birth of the phenomenon;        a single-alternation conduction phase corresponding to a dielectric breakdown with an increase of intensity;        a double-alternation conduction phase; and        an arc tracking phase. This last phase is a phase of electrical discharge of limited intensity propagating along electrical cables which may lead to the partial or total destruction of a bundle of electrical cables as a result of carbonization of the cable insulation.        
Apart from deterioration of the insulation of an electrical cable, a loosened connection and abrasion of a cable are also propitious to the appearance of electrical arcs.